A microwave communications technology is mainly applied to a wireless communications scenario with a demand of large bandwidth. In the microwave communications technology, a multipath communications technology is a communications technology that is relatively common, and in the multipath communications technology, each path uses a similar spatial channel, and therefore, interference exists between the paths. When the interference is relatively strong, correct transmission of data inside each path is affected, leading to a communication failure; therefore, how to cancel the interference between the paths is a problem to be resolved urgently.